Update, arrived two days ago at my ASQ, everything went well except there was a mistake on my COE as my transit was on December 26, not 25 and made my boarding slightly complicated.
We were at Arjaan Rotana Creek, the rooftop pool view was great and it was low season price (October) but far from everything, ended up renting a car, so not sure I would recommend...
Exactly, you can do it at the Canada Post office at the same time as your money order. One envelope with postal tracking (for safety) but you also need to provide another prepaid envelope with your address, so they can send back your passport. Cost about 35$ for 2 envelopes. Now I’m waiting for my visa, nothing to do. When I’ll get it, then: PCR test, Fit to fly certificate, booking my flights, quarantine hotels and COE. 😅